This document discusses the use of ultrasound guidance for nerve blocks. It begins with an overview of the rationale for using ultrasound, which is to improve block success and safety by directly visualizing nerves and needle placement. It then covers ultrasound principles, equipment, probe selection and scanning techniques. The document provides detailed guidance on performing ultrasound-guided nerve blocks of various peripheral nerves and plexuses, including anatomy, probe positioning and needle approaches. It emphasizes the importance of ultrasound machine and probe quality, anatomical knowledge, and needle visualization for successful ultrasound-guided regional anesthesia.